This invention relates generally to medical equipment, and more particularly to an adapter for xe2x80x9cLUER LOKxe2x80x9d receptacles, and to a method of attachment to xe2x80x9cLUER LOKxe2x80x9d receptacles.
One well known receptacle used to connect and establish fluid communication between different medical components is known as a xe2x80x9cLUER LOKxe2x80x9d. xe2x80x9cLUER LOKxe2x80x9d receptacles are widely used to connect syringes to medical instruments, such as needles and cannulas, and to connect medical conduits to one another. In addition, xe2x80x9cLUER LOKxe2x80x9d receptacles have a standard configuration that allows different sizes and types of instruments to be connected to the same receptacle.
Referring to FIGS. 1A-1F, a syringe 10 that includes a xe2x80x9cLUER LOKxe2x80x9d receptacle 12 is illustrated. As shown in FIGS. 1A and 1B, the syringe 10 includes a barrel 14, and a plunger 16 configured to push a liquid or viscous fluid through the receptacle 12 and out of or into the barrel 14. As shown in FIG. 1C, the receptacle 12 includes a cylindrical hub 18 having an outside diameter with a finished surface, and an inside diameter threaded with double lead female threads 20. The hub 18 is sometimes referred to as the xe2x80x9cfemalexe2x80x9d portion of the receptacle 12.
The receptacle 12 also includes a tapered post 22 located partially within the hub 18 but which extends outside of the confines of the hub 18. As with the outside diameter of the hub 18 the outside surface of the tapered post 22 is also smooth. The tapered post 22 is sometimes referred to as the xe2x80x9cmalexe2x80x9d portion of the receptacle 12, and is sometimes referred to as a xe2x80x9cLUERxe2x80x9d tapered coupling. Typically, the hub 18, the tapered post 22, and the barrel 14, all comprise a same plastic material, which is molded into a unitary structure using an injection molding process.
Referring to FIGS. 1E and 1D, a cannula 24 configured for attachment to the receptacle 12 is illustrated. The cannula 24 includes a hollow cylindrical tip portion 26 on its distal end. The tip portion 26 includes an inside diameter which provides a fluid conduit, and a sharpened post 28 in fluid communication with the inside diameter. The cannula 24 also includes a knurled portion 30, and a threaded or flanged male portion 32 formed on an outside diameter thereof on its proximal end. In addition, the cannula 24 includes a tapered opening 34 in fluid communication with the inside diameter of the tip portion 26, and with the sharpened post 28. The tapered opening 34 is configured for mating engagement with the tapered post 22 of the receptacle 12.
Referring to FIG. 1F, the cannula 24 is shown attached to the receptacle 12. For attaching the cannula 24 to the receptacle 12, the tapered post 22 of the receptacle 12 is placed into the tapered opening 34 of the cannula 24. The mating configurations of the tapered post 22 and the tapered opening 34 forms a fluid tight seal therebetween. At the same time, the cannula 24 is twisted in a clock wise direction, so that the male threads 32 on its outside diameter, threadably engage the female threads 20 on the inside diameter of the hub 18. This twisting motion also xe2x80x9clocksxe2x80x9d the cannula 24 to the receptacle 12, and forms another fluid tight seal between the male threads 32 and the female threads 20.
This conventional xe2x80x9cLUER LOKxe2x80x9d receptacle 12 is used effectively throughout the world, but still has several disadvantages. One disadvantage is that the receptacle 12 is prone to crack and break, particularly at the intersection 36 (FIG. 1C) of the hub 18 with the syringe barrel 14, and at the intersection 38 of the tapered post 22 with the syringe barrel 14. This cracking and breaking compromises the strength of the mechanical connection between the receptacle 12 and the cannula 24, and compromises the fluid tight seals between the receptacle 12 and the cannula 24. Fluids leaking from the syringe 14 are a particular problem as they can adversely affect a medical procedure, and also present a biological hazard to patients and medical personnel.
This situation is compounded by cannulas, or other instruments, which are relatively long, or which require aggressive manipulation by medical personnel. For example, harvesting of tissue and cells from different organs of the body, requires relatively long cannulas and aggressive manipulation by physicians, which can damage the receptacle 12. In addition, the twisting motion required to lock the cannula 24 to the receptacle 12, can cause the hub 18 to expand outwardly during engagement of the male threads 32 on the cannula 24 with the female threads 20 on the receptacle 12. This expansion can also cause cracking and breaking to occur, or can cause micro cracks that lead to cracking and breaking.
Another disadvantage of the conventional xe2x80x9cLUER LOKxe2x80x9d receptacle 12 is that the inside diameter (ID-FIG. 1C) of the tapered post 22 is relatively small. Typically this inside diameter (ID-FIG. 1C) is only about 1.9-2.0 mm in size. An opening this small can cause problems for some medical procedures. For example, with harvesting of tissue and cells from the body, it is advantageous to treat the harvested material as gently as possible, in order to minimize damage and trauma. With a relatively small inside diameter (ID-FIG. 1C) the harvested material is squeezed into a relatively small area which can damage the material. Also, the relatively small diameter column of fluid moving through the inside diameter (ID-FIG. 1C) means a large percentage of the harvested material can be damaged by contact with the inside diameter (ID-FIG. 1C) of the tapered post 22.
The present invention is directed to an adapter for xe2x80x9cLUER LOKxe2x80x9d receptacles which functions to strengthen, to rigidify, to prevent spreading, and to prevent cracking of the receptacle. In addition, the adapter can be used to increase the inside diameter of the receptacle, such that medical fluids and/or harvested cells and tissue, can be more effectively processed.
In accordance with the present invention, an adapter for a xe2x80x9cLUER LOKxe2x80x9d receptacle, and a method for attaching a medical instrument to the receptacle, are provided.
The xe2x80x9cLUER LOKxe2x80x9d receptacle can be molded on a first medical instrument, such as a syringe, substantially as previously described. The receptacle includes a cylindrical hub having a smooth outside diameter, and a threaded inside diameter having female threads. The receptacle also includes a tapered post located partially within the hub, but extending outside of the confines of the hub.
The adapter is configured for attachment to the receptacle, and functions to strengthen and rigidify the receptacle. The adapter includes a generally cylindrical housing, which preferably comprises a rigid material such as metal, hard plastic or a composite. The housing includes a cylindrical recess configured to slip over the outside diameter of the hub on the receptacle. The inside diameter of the recess is sized relative to the outside diameter of the hub to provide a press fit, and also to seal the mating surfaces. Alternately, rather than a press fit, the inside diameter of the recess can be threaded with cutting threads adapted to cut mating threads on the outside diameter of the hub.
The adapter also includes a fitting which is attached to the housing, and to a second medical instrument, such as a cannula or a needle, having an internal conduit. The fitting includes an internal conduit in flow communication with the internal conduit on the second medical instrument. The fitting also includes a male end portion located within the recess, configured to engage the female threads on the hub of the receptacle. The male end portion can include male threads on an outside diameter thereof configured to threadably engage the female threads on the hub. Alternately the male end portion can have a flange, termed herein as a xe2x80x9cbutterflyxe2x80x9d, which is configured to engage the female threads on the hub. The fitting also includes a tapered recess in the male end portion configured to slip over the tapered post on the receptacle. As with the recess in the housing, the tapered recess is sized relative to the tapered post to provide a press fit, and also to seal the mating surfaces.
For attaching the adapter to the receptacle, the recess on the housing of the adapter is slid onto the hub on the receptacle (or alternately threaded onto the hub in the threaded embodiment). At the same time, the tapered post on the receptacle is slid into the tapered recess on the fitting of the adapter. The housing of the adapter is then twisted, such that the male end portion on the fitting engages the female threads on the hub. As thus attached, the recess in the housing encircles the hub on the receptacle to rigidify and prevent spreading of the hub. In addition, a first fluid tight seal is formed between the male end portion on the fitting and the female threads on the hub, a second fluid tight seal is formed between the tapered post and the tapered recess, and a rigidifying seal is formed between the recess and the hub. The rigidifying seal is not necessarily fluid tight but is configured to provide a rigidifying structure, and to prevent movement of the first and second fluid tight seals.
In an alternate embodiment of the adapter, the tapered post on the receptacle is removed, such that an enlarged opening is provided on the first medical instrument. In addition, the second medical instrument, and the fitting on the adapter, are provided with internal conduits having diameters matching that of the enlarged opening. The alternate embodiment adapter also includes a housing having a recess configured to slip over, or alternately to cut threads on the outside diameter of the hub of the receptacle. The enlarged opening permits fluids, tissue and cells to be transferred through the receptacle with less resistance and less damage.
The method for attaching the medical instrument to the receptacle includes the step of providing the adapter with the housing, the fitting, and the second medical instrument as described above. The method also includes the steps of slipping (or alternately threading) the recess in the housing to the outside diameter of the hub on the adapter, and slipping the tapered post on the receptacle into the tapered recess in the fitting. In addition, the method includes the step of twisting the housing to threadably engage the threads (or the flange) on the male end portion of the fitting with the female threads on the hub.